The Science of Jealousy
by myhomeistheshire
Summary: Simmons has been in love with Fitz since he showed up in her university lab, but after three years of pining, she decides to go out with the new field agent Adam.


Simmons was studying for an upcoming exam when she first met him. She'd had her hair pulled back and the safety glasses on, and when he'd tapped her on the shoulder she'd jumped so hard she'd nearly tipped over the beaker she was studying. Turning, she saw a boy her own age with curly hair and the most adorable smile she'd ever seen. "Sorry - sorry." She said, not knowing why she was apologizing for him startling her.

"No, that was my fault." He said, looking apologetic and a bit mortified. "I didn't mean to startle you, I just - we're in a few of the same classes, and, um, I was just wondering if maybe you wanted to study together. I know it's not anything really hard - they're just basic courses, but still -"

"I'd love to." Simmons said, her face a little flushed for reasons unknown to her. "I mean, yeah, that'd be fun. Er - not fun, but you know - educational."

"Educational." He agreed, and Simmons could've been imagining it but she thought there might have been a bit of a flush to his face as well. "Right. Well, then - should I meet you in the library tonight at 7?"

"Sure." Simmons agreed. "Oh, wait -" She called as he turned to leave. He looked back at her, questioning. "I, um, I didn't get your name."

"Oh, right." He said, embarrassed. "Leo Fitz. But I usually just go by Fitz."

"Jemma Simmons. And I usually go with the last name, as well. Makes it much simpler, doesn't it?"

"Yeah." Fitz agreed, looking relieved to be on more solid ground. "Less use of common names, at least. So - tonight, at 7?"

"Right, perfect." Simmons said with another flustered grin, tucking piece of hair behind her ear that had fallen out. Fitz shot her another one of those adorable awkward smiles before he turned and walked out. Simmons turned back to her work, but gave up after an hour of not being able to concentrate. Her heart was still beating fast, and for some inexplicable reason she found herself stopping by her room to change before heading down to the library.

Three years later, and look where they were. Working with S.H.I.E.L.D., doing _field work_ for god's sake. It was much different from what she'd imagined, but Simmons loved it. It gave her a challenge - there was always some new enigma, be it alien technology or a completely different element that had been created by a madman in an iron suit. And she got to work with Fitz every day. He drove her mental sometimes, but Simmons didn't know how she would get along if he wasn't there. But she knew that she was the only one who felt that way, so she kept it to herself, pretending that she didn't care when he talked about the newest girl that he was infatuated with. She knew if she let herself think that there was any chance for them, there would be no mending her broken heart. So when on one expedition she ended up partnered with a field agent that _wasn't_ Fitz, she pretended that she didn't mind. Of course not, it was fine, Fitz could handle being without her for one assignment.

The field officer she was paired with was tall, dark-haired, and she couldn't help but notice, dashingly handsome. "My name's Agent Barre." He said when they'd first met, then flashed her a smile and added, "but you can call me Adam."

"Nice to meet you, Adam." Simmons said, smiling politely as she shook his hand. "I'm Simmons."

"Simmons?" He asked, raising an eyebrow.

"Jemma - sorry. My name's Jemma Simmons. But, um, I usually just go by Simmons."

"How about Jem?" Agent Barre - _Adam _asked with an insouciant grin.

"Jem? That's, ah, that's fine." Simmons said, a little flustered. Why was she flustered? Blast it, life would be so much easier if she could just discern her own emotions all the time.

"Alright, enough of that." Coulson said from behind her. Simmons turned to face him, and saw that from a little ways away Fitz was watching her. He turned away as soon as he saw her looking. "- So we need to get right on that." Coulson was finishing.

Oh, _fudge._ Now she hadn't even heard the basics of the assignment. Seems like she'd have to catch up on the details with her new partner a bit later.

As luck would have it, when she was in her room a little while later a knock came at her door. She finished writing the sentence she was on, describing what they'd learned about alien technology so far before answering it.

She was expecting Fitz or Skye or even Ward, but to her surprise when she opened the door there was Adam, standing in her doorway.

"So I was thinking," He said before she could even register her astonishment, "we might need to go over some of the details of the assignment. And there's this really nice restaurant I know of in downtown NYC, which as it happens, we've stopped in currently." He leaned against the doorway. "So what'd you think?"

"That would be fantastic." Simmons said, relieved. Thank _goodness_ he'd seemed to notice her blanking out earlier. She glanced over at the clock, which read 7:00 pm. "Should we go now? Or would tomorrow be a better time for your schedule?"

"Nope, tonight's all yours." Adam responded.

"Good, alright, I'll just - grab my stuff and meet you downstairs?" Simmons asked. Adam lifted one hand up in acquiescence.

"Go ahead. I'll see you in a few." And with that he turned and walked down the corridor. Simmons felt a pit in her stomach - excitement, right? Because, when she thought about, this was probably meant to be a date. And it was about time she went out with someone instead of waiting around for Fitz. But - no. She had to go on with her life. So she grabbed her bag and headed down the stairs to meet him.

They had a good time at the restaurant - it was a really quaint place, if a bit expensive and over-the-top. But when Simmons tried to pay, Adam insisted on taking the cheque, which solidified her question as to whether or not this was a date. And he really was sweet, even walking her back to her room when they were done. When they reached her door, Simmons stopped and turned around.  
"Thanks again, Adam." She said, not really sure what one said after a date. "It was a really lovely restaurant." She had the feeling that Adam was waiting for something, but when she didn't say anything else he nodded and reached up to tuck a piece of hair back behind her ear, letting his hand linger there for much longer than was needed.

"Goodnight, Jem." He said, and then without another breath leaned down and kissed her.

Simmons froze up, not quite knowing what to do. Eventually she relaxed and kissed him back, but she still had the feeling that something was off. And then he pulled away and disappeared down the corridor, leaving her with her muddled emotions.

Someone cleared their throat behind her, and Simmons jumped, turning to see Fitz standing outside his doorway.

"What - I thought you'd be asleep by now." Simmons said, attempting to fight the redness rising in her cheeks.

"Yeah, well, hard to do when you've got two people snogging right outside your room." Fitz said in annoyance. "The walls here aren't that thick, you know."

Simmons flushed even brighter. "Well, you can go down to the lab, you know." She retorted sharply to conceal her embarrassment. "No one asked you to _lurk_ around here making snide comments."

Fitz snorted. "Oh, so now I'm the one lurking?" He seemed to be in an incredibly foul mood, although Simmons could hardly think why. Long day in the lab, perhaps. "I'd rethink that word next time, with you sneaking around with your boyfriend in the dead of night -"

"It is not the _dead of night_, and we were hardly sneaking -"

"- and since when do you go by Jem? Bloody stupid, if you ask me -"

"- well no one did, and for your information I can go 'round with whomever I decide -"

" - don't know what you see in the bloke, with his gelled up hair -"

" - and I'm tired of you trying to run my life for me, I've got my mum for that, thanks -"

" - for god's sake the man's basically a moron, do you even think he can name -"

" - and I don't know why you're being so ridiculous about this, or why you'd even _care -"_

Fitz stopped talking, at that, and Simmons was so surprised she shut up midsentence. He had an almost furious expression on his face, but looked down before she could work it out.

"Why the hell do you _think _I care?" He asked, his voice so low that she almost couldn't hear him.

"I don't know, Fitz." Simmons said, suddenly furious at him for the first time in ages. "I don't know what you think, or why you act the way you do sometimes, or why you even still bother with me when you so obviously don't give a damn about anything except the company I choose to keep!" Her voice was hoarse, and she had to swallow a lump that had risen in her throat. Tears threatened to spill over, but she blinked them back furiously, ducking her head so Fitz wouldn't see.

"Is that what you really think?" His voice rose to match hers. "Because I'm sure I'm not the only one who doesn't give a damn, Simmons, you've made it obvious that you're quite fine without me now that you've got your precious _Adam_, or was I mistaken? _You're_ the one who doesn't give a rat's arse about me, even though I've made it bloody clear that I'm in love with you!"

Simmons' heart stopped beating, and for a moment she could've sworn time froze. "What?" She managed to whisper finally. She must've heard him wrong, there was no way he'd said something like that.

"I said that I'm bloody in love with you." Fitz snapped, avoiding her eyes now. Simmons tried to think up something to say, but her mind, usually the one thing she could rely on, was a complete mess. "I should go." Fitz said, turning, but Simmons' brain managed to stutter awake at that.

"No - Fitz, wait, please." Fitz turned back, finally glancing up and meeting her gaze. Simmons took a deep breath to steady herself as she started talking again rapidly. "I didn't - you were always so indifferent and - and you talked about all those other girls and I never I _never _let myself think that -" Fitz's expression was changing, to a shocked disbelief and then possibly a flash of hope. " - That you might actually - and then Adam asked me and I thought that maybe I would be able to stop thinking about you but I couldn't and -"

Simmons stopped speaking as Fitz reached down and kissed her. It took a moment for her mind to stutter awake and then she was kissing him back, and for once not thinking of anything else, and her heart was filling up with emotions she'd never dreamed it was capable of holding.

When they finally broke apart Fitz's hands stayed cupped around her face. They were both flushed, breathing heavily.

"Simmons." Fitz said, looking at her in a way she'd never allowed herself to want, "do you believe me now?"

"Yes." Simmons breathed out. And then he was kissing her again in a way that made her never want to him to stop. And she knew, unrefutably, that at that very moment she was the happiest person alive.


End file.
